When building a model of any kind, it is important to make sure that all of the various pieces of the model are aligned and securely attached to one another. This is important not only for aesthetic reasons but also to allow an operating model to function properly. One of the most important sections to assemble with respect to a model airplane is the empennage section. This section, which is also known as a tail assembly, includes flight control surfaces known as the vertical and horizontal stabilizers.
In order for an aircraft to properly fly, the empennage must be precisely aligned and attached to the fuselage. The need for this alignment is self-evident to anyone who has ever flown a real or model airplane, as the empennage and its component parts, the vertical and horizontal stabilizers, are critical to the control and stability of the aircraft.
The vertical stabilizer (also called the tail fin) includes the control surface known as the rudder. The rudder is used to control the aircraft's motion along the yaw axis and thus allow the nose of the aircraft to move left or right. The rudder is also important in aiding the pilot with maintaining what is known as balanced flight during a turn. This is because correct positioning of the rudder results in the tail of the aircraft directly following the line of flight of the nose of the aircraft through a turn, thereby eliminating a skidding or slipping of the aircraft.
The horizontal stabilizer controls the aircraft's motion along the pitch axis. This control surface allows the nose of the aircraft to pitch up or down so as to allow the airplane to climb or descend. Both the horizontal and vertical stabilizers work in conjunction with the ailerons on the wings to allow the airplane to move in all three axes (i.e., yaw, pitch and roll). Needless to say, if either the vertical or the horizontal stabilizer should separate from the aircraft, catastrophic results could occur. For this reason, it is important that a model aircraft have an empennage assembly that can be easily and securely fastened to the fuselage. In addition, for the model enthusiast, it is important to have an empennage assembly that can be attached to a model airplane by hand without the use of tools.